For those of you who have been around for a minute on this board you remember when i showed the pictures of mine taking on some water. I took mine to Jiffy and i stood there and watched them do everything. I make sure i go to shops where i can talk to the guy and watch him do it. Being that i had salt water in the trasnmission i needed to do a full flush including all that was in the torque converter. I watched the machine and we flushed 30 quarts threw the truck before it came clean. I'll stick with them until they prove otherwise on good workmen ship. The dealer wanted just under $400 for the flush on the tranny and you know after the 10 quarts they would have started charging extra the guys at jiffy didn't.

 

Pan drop only gets 7qts of fluid changed. Then your mixing new fluid with all the rest of the old fluid "bad" fluid that your looking to change.
Full flush requires about 17qts.
I would not use a cork gasket, Either rubber or use Permatex 1-Minute gasket maker. That stuff is fantastic and sets up real quick. If you drop your return line and start your truck up and let the fluis pump itself into a nucket, you can drop your pan with zero mess.

No quicklube will change filters in the pan when doing a flush unless you pay additional for it.
Also, the 60kmi change is a complete flush, not just a pan drop...fyi